ML13179A095

Davis-Besse Nuclear Power Station Request for Alternative RR-A37 - Request for Additional Information

ML13179A095
Person / Time
Site:	Davis Besse
Issue date:	06/27/2013
From:	Purnell B A Plant Licensing Branch III
To:	Lashley P H First Energy Services
References
TAC MF0752
Download: ML13179A095 (4)

Text

1 NRR-PMDAPEm Resource From:Purnell, Blake Sent: Thursday, June 27, 2013 10:56 AM To: phlashley@firstenergycorp.com Cc: cjheintz@firstenergycorp.com; 'j hofelich@firstenergycorp.com'

Subject:

Davis-Besse Nuclear Power Station Request fo r Alternative RR-A37 - Request for Additional Information (TAC No. MF0752)

Attachments:

Davis-Besse Relief RR-A37 RAI (MF0752).pdf Mr. Phil Lashley:

By letter dated February 27, 2013, FirstEnergy Nuclear Operating Company (the licensee) submitted Request No. RR-A37 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML13059A315) for U.S. Nuclear Regulatory Commission (NRC) review and authorization. The proposed alternative requests acceptance of limited examination coverage of the Cold Leg 1-2 Drain Nozzle to Pipe dissimilar metal butt weld and the associated full structural weld overlay at Davis-Besse Nuclear Power Station. The NRC staff has reviewed your request and has determined that additional information is needed to

complete the review. In order to support the schedule for NRC review of your request, please provide a response to the attached request for additional information within 30 days of the date of this email.

This email serves as the official NRC request for additional information and a copy of this email will be placed into ADAMS and made pub licly available.

Docket No. 50-346

Sincerely, Blake Purnell, Project Manager Plant Licensing Branch III-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission

ph: 301-415-1380

Hearing Identifier: NRR_PMDA Email Number: 738 Mail Envelope Properties (Blake.Purnell@nrc.gov20130627105500)

Subject:

Davis-Besse Nuclear Power Station Request for Alternative RR-A37 - Request for Additional Information (TAC No. MF0752) Sent Date: 6/27/2013 10:55:31 AM Received Date: 6/27/2013 10:55:00 AM From: Purnell, Blake Created By: Blake.Purnell@nrc.gov Recipients: "cjheintz@firstenergycorp.com" <cjheintz@firstenergycorp.com> Tracking Status: None

"'jhofelich@firstenergycorp.com'" <jhofelich@firstenergycorp.com> Tracking Status: None "phlashley@firstenergycorp.com" <phlashley@firstenergycorp.com> Tracking Status: None Post Office: Files Size Date & Time MESSAGE 1263 6/27/2013 10:55:00 AM Davis-Besse Relief RR-A37 RAI (MF0752).pdf 77170 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date: Recipients Received:

REQUEST FOR ADDITIONAL INFORMATION REQUEST NO. RR-A37 FIRSTENERGY NUCLEAR OPERATING COMPANY DAVIS-BESSE NUCLEAR POWER STATION DOCKET NO. 50-346 TAC NO. MF0752 By letter dated February 27, 2013, FirstEnergy Nuclear Operating Company (the licensee) submitted Request No. RR-A37 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML13059A315) for U.S. Nuclear Regulatory Commission (NRC) review and authorization. The proposed alternative requests acceptance of limited examination coverage of the Cold Leg 1-2 Drain Nozzle to Pipe dissimilar metal butt weld (DMBW) and the associated full structural weld overlay (FSWOL) at Davis-Besse Nuclear Power Station. In order to complete the review, the NRC staff requests additional information.

1. The licensee states in Proposed Alternative and Basis for Use: Based on radiological survey results from the spring 2012 refueling outage, this work would occur within radiation fields with dose rates up to 500 milli-Rem per hour, resulting in a significant increase in occupational radiation exposure [dose] to personnel. The Examination Data Sheet for the examination performed on May 15, 2012, indicated that the examination required nearly one hour, but the UT Examination Summary documented a total dose of 32 milli-Rem for the examination.

a. Explain the apparent discrepancy in the dose rate and the total radiological dose. b. Justify why the dose incurred would present a hardship.

2. The NRC staff is unable to determine the exact volumes that were examined and the part of the required volume that was not examined from the drawings provided in the proposed alternative.

Provide clear scale drawings (with scale indicated) of the subject DMBW, including weld butter and FSWOL indicated. Clearly show the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (Code) Case N-770-1 required examination volume and the volume of material interrogated by the examination in the axial and circumferential scan directions.

3. Provide a table detailing the scan coverage achieved for each of the following:

a. carbon steel nozzle; b. stainless steel elbow;

c. susceptible weld metal; and d. full structural weld overlay.

Provide values for scans in the circumferential and axial directions.

4. The licensee states that limitations imposed by the weld geometry resulted in incomplete scan coverage. Describe these limitations and their effects on scan coverage.

5. The technical report detailing the preservice examination of Cold Leg Drain Nozzle 1-2 (ISI Component ID RC-40-CCA-18-3-FW9) FSWOL in 2010, Summary of Weld Overlay Ultrasonic Examinations for Reactor Coolant Pump Suction and Discharge Welds, Core Flood Nozzle Welds, and Cold Leg Drain Line Welds at Davis-Besse Nuclear Power Station, Unit 1 (ADAMS Accession No. ML101230641), states 100 percent axial scan coverage and 80.1 percent circumferential scan coverage of the ASME Code Case N-740 [8] required volume, as documented in the Relief Request [5], was achieved during the examinations.

a. Why does the current examination not achieve 100 percent coverage for scans in the axial direction and at least 80 percent coverage for scans in the circumferential direction? b. Provide a detailed explanation for the differences in examination coverage between the preservice and the current inservice examination.

6. Provide a copy of the Performance Demonstration Qualification Summary (PDQS) for the UT examination procedure used. Describe any limitations of the ASME Code,Section XI, Appendix VIII qualified examination procedure.

7. Was the subject inservice examination performed by team scanning?